According to the World of Famous Gems website, the finest sapphire gems come from Sri Lanka and Burma.
The stones that have been eroded from Sri Lanka’s central mountains are still plucked by hand from gravel deposits that cover most of the southern half of the island. These precious stone are typically light to medium blue, and gemstones have been cut that weigh up to several hundred carats.
The U.S. National Gem Collection boasts one of the largest fine blue sapphire gems, the 422.99-carat Logan Sapphire from Sri Lanka. It is the heaviest mounted gem in the National Gem Collection, and is framed in a brooch setting surrounded by twenty round brilliant-cut diamonds, totalling 16 carats.
The piece was a gift to the Smithsonian Insitute from Mrs. John A. Logan in 1960. Source: The National Gem Collection by Jeffrey E. Post.
ABOUT THE VIDEO
I filmed this piece in Washington, D.C., 2009.